A semiconductor device is widely produced using an electronic device comprising a circuit on the surface of an insulating base. Below, the structure of a conventional electronic device will be briefly explained.
An electronic device 100 shown in FIG. 4 comprises an insulating base 110, an adhesive layer 120 which is formed on the entirety of one surface of the insulating base 110, and a circuit 130 which is formed on the surface of the adhesive layer 120. The circuit 130 is produced by pattern formation of metal portions 131 made of copper and the like, and, for example, this is formed by attachment of a metal foil and pattern formation.
If such electronic device or a semiconductor device comprising such an electronic device is used, metal contained in the circuit is ionized and gradually migrates into the adhesive layer. Thereby, there may be cases in which insulation performance decreases and a plurality of metal portions comprising the circuit are electrically conducted to each other via the adhesive layer. This problem is serious when the electronic device or the semiconductor device is used in high-temperature low-humidity conditions or high-temperature high-humidity conditions.
A technique in that the adhesive layer is made of resin compositions, in which when metal contained in a circuit is ionized, it does not readily migrate, has been suggested (for example, Japanese Unexamined Patent Applications, First Publications Nos. Hei 8-238713 and Hei 11-181233). However, when the electronic device or the semiconductor device is used in high-temperature low-humidity conditions or high-temperature high-humidity conditions, the problem is not sufficiently solved by merely changing the compositions of the adhesive layer.